As a positive electrode active material for lithium ion battery, a lithium transition metal composite oxide is well known. The lithium transition metal composite oxide is produced as described, for example, in Patent document 1 in such a manner that a lithium compound and a transition metal compound are mixed to prepare a precursor for positive electrode active material for lithium ion battery and, after that, the mixture is fired to form a composite.
A lithium ion battery is, from the uses thereof, used over a long period of time, and, because charge and discharge are repeated, various kinds of characteristics such as the cycle characteristics and storage characteristics are required, and high capacity of very high level is being demanded. Further, as a market for lithium battery for use in consumer equipments such as portable telephones and personal computers and for use in automobiles expands, it is demanded to produce lithium ion battery at low cost and with high efficiency.
In a step of producing lithium ion battery like this, as was described above, it is necessary to fire a precursor for positive electrode active material for lithium ion battery to form a composite. In such a step of firing, generally, a method where a firing vessel in which the precursor is filled is disposed inside of a firing furnace (static furnace) and heated according to a conveyer method or a batch method is in use. In the case of conducting the firing by using the static furnace, a large amount of precursor can be fired relatively efficiently by sending the firing vessel in which a large amount of the precursor is filled into the furnace in sequence.
(Patent documents 1) Japanese Patent No. 3334179